Electrical stop motion for knitting machines



W. ARROWOOD ELECTRICAL STOP MOTION FOR KNITTING MACHINES April 19, 1949.

2 Sheets-Sheet 1 Filed Jan. 51, 1947 CHARLES w. ARROWOOD,

Swan/rm.

April 19, 1949. c. -w. ARROWOOD 2,467,366

ELECTRICAL STOP MOTION FOR KNITTING MACHINES Filed Jan. 51, 1947 2 Sheets-Sheet 2 CHARLES w. ARRowoou,

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o 1 47 68- 331g V fittoww Patented Apr. 19, 1949 UNITED STATES PATENT OFFICE ELECTRICAL STOP MOTION FOR KNITTING MACHINES Claims. 1

This invention relates to a stop motion device for knitting machines, and more especially to a stop motion especially adapted for use in the knitting of nylon yarn. Nylon yarns are of a Very much finer denier than ordinary rayon or silk yarns and therefore ordinary stop motions which have been used on rayon yarns and the like sometimes will not properly operate with nylon yarn. I have devised a very sensitive stop motion, which not only will be operable to stop the machine upon a parting of the yarn but which will automatically regulate the tension of the yarn, and will also automatically lock itself in position when the yarn becomes too slack to prevent the stop motion through which the yarn is passing from stopping the machine due to the slackness of the yarn.

This application is a continuation in part of the structure shown in my co-pending patent application, Serial No. 687,449, filed July 31, 1946, now Patent Number 2,420,513 of May 10, 1947.

It is an object of this invention to provide a stop motion having means for holdin an electrical circuit in open position while the yarn is not parted and while it has proper tension thereon and which upon parting of the yarn or upon the tension in the yarn becoming too great, serving to close the electrical circuit and this electrica1 circuit being associated with stop motion means such as belt shifting means and the like, not shown, will thus stop the machine.

It is another object of this invention to provide an electrical stop motion adapted to be associated with a strand of yarn such as employed in knitting machines and the like which will lock the stop motion against operation to close an electrical circuit when the slackness in the yarn becomes too great such as slackness in the yarn when a particular yarn is not being knitted in the knitting machine and this yarn is idle and due to vibration of the machine sometimes the slackness in the yarn becomes very great and means are provided in this stop motion for preventing closing of the circuit due to this excessive slackness in the yarn.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings in which Figure 1 is an elevation with parts in section of an arm of a bracket adapted to be secured on a vertical post of the machine not shown and showing the invention mounted on said arm;

Figure 2 is an elevation looking from along the line 2-2 in Figure 1 and showing the arm in section, and showing portions of the transparent side broken away;

Figure 3 is a View partly in section and partly in elevation and taken along the line 3-3 in Figure 1 and showing portions broken away;

Figure 4 is a view taken along the same line as Figure 3 and showing some of the parts in a different position;

Figure 5 is a view similar to Figures 3 and 4 but showing the parts in still another position;

Figure 6 is a view similar to Figure 5 but showing the parts in still another position such as when a thread has parted;

Figure 7 is a view in elevation with parts in section and taken along the line '|'l in Figure 1;

Figure 8 is a detail view showing a portion of the lower central portion of Figure 2;

Figure 9 is a top plan vieW of the structure shown in Figure 1;

Figure 10 is a vertical sectional view taken along the line Ill-l 0 in Figure 2;

Figure 11 is a sectional plan view taken along the line I [-1 I in Figure 2;

Figure 12 is a view similar to Figure 8 but showing the parts in a difierent position.

Referring more specifically to the drawings, the numeral [0 indicates an arm of a bracket which is usually attached to the upright post of a circular knitting machine, there being several of these arms or one for each cone of yarn which may be employed in the knitting machine. In the event that this stop motion should be used in conjunction with a full-fashioned knitting machine, it of course would be mounted on a suitable part of the framework of the machine. This arm I0 is grounded or forms one part of an electrical circuit associated with a stop motion, a bell, a lamp or any other conventional arrangement for stopping the machine upon parting of the yarn or probably giving a signal in addition to stopping of the machine. The arm [0 has rising upwardly therefrom and secured thereto in any suitable manner such as screws 9 an upright ll having an outturned portion [2 provided with a slot l3 therein. This member H has penetrating the same a suitable bolt l4 having an insulated sleeve l5 thereon with a pair of conventional tension discs I! and I8 which are pressed into engagement with each other by a compression sprin I9. Threadably mounted on the bolt I4 is a thumb nut 2| which is adjusted to give the proper compression on spring l9 and this thumb nut is usually secured in position by a jam nut 22.

Rotatably mounted in the upright H is a small shaft 25 having an upwardly and inwardly projecting portion 26 viewed in Figure 3, for example, which is adapted to pass between 'the tension discs I1 and Hi to relieve the tension on the yarn 21 passing therethrough. This yarn is adapted to pass from a suitable cone not shown through an eyelet 2B and between the tension discs I! and I8 and on the far side of a horizontal portion 30 of an upright portion 36 as viewed in Figure 1, which is integral with another small shaft 32. The presence of the yarn between portion 35 and portion l2 prevents the portion 39 from passing through the slot l3 as will be later described.

Penetrating the arm I is a bolt 35 which is surrounded by an insulating sleeve 36 to insulate it from the arm 10. The upper end of bolt 35 penetrates the bottom of a housing or upright portion 3'! and immediately above the bottom surface of the housing 3'! is an insulating washer 38 and also there is an insulating washer 39 disposed against the lower surface of arm It). A suitabl nut 4i secures the bolt in position and to this bolt 35 is connected a wire 42 which is secured on the bolt 35 by a nut '43. On top of the insulating washer 38 and below the head of the bolt 35 is a leaf spring contact member 44 which projects rearwardly and upwardly in Figure 1 and is better illustrated in Figure 2.

The housing 3'! is covered by a transparent pane 47 through which the parts on the interior of housing 31 can be viewed. This transparent pane 4'! is removably secured in position by means of screws 48. The small shaft 25 oscillatably penetrates the vertical Wall of the housing 31 and also the transparent pane 41 and has secured on the lefthand end thereof in Figure 1 a collar 50 by means of a set screw Extending from this collar 50 is an arm .52 which has a forked member 53 thereon through which the yarn passes after passing through the tension discs I? and I8 and through a suitable eye disposed thereabove, but not shown, and then the yarn passes through the member 53 and then to another suitable eye member located above the level of the stop motion from whence it usually goes to a yarn feed finger.

The small shaft 32 adjacent the vertical wall of housing 31 has a collar 55 adjustably secured thereon by any suitable means such as a set screw 56 and this collar has a cavity 5'! in the lower left-hand surface thereof as viewed in Figure 7. The small shaft 25 has welded thereto an arm 60 which is adapted to engage the cavity 5'1 to lock the small shaft 32 against movement under certain conditions to be hereinafter explained, such as for example, when the yarn gradually loses its tension, this will lock the shaft 32 against movement and prevent the uprising portion ill from falling away from the observer in Figure 1 and causing stoppage of the machine.

Rotatably mounted in the upper portion of the side wall of the housing 37 is a short shaft 60' on which is fixed a knurled knob 6| by means of a screw 62. Around this shaft on the inside of the housing is oscillatably mounted a contact member 63. The shaft 60' has disposed therearound a torsion spring 64 which has one end thereof anchored as at 65 in the end of the shaft while its other end projects downwardly and is hooked behind the oscillatable member 63 as shown in Figure 2. This knurled knob 6| has a set screw 61 threadably mounted therein which is adapted to penetrate one at a time i the holes 68 in the vertical side wall of the housing 31 to thereby hold the proper tension on the torsion spring 64 when the knurled knob is rotated sufliciently to give this desired torsion in the spring 64.

Adjustably mounted on the shaft 25 is a collar E3 by means of a set screw H. This collar 10 has a flattened surface 13 towards which the lower end of the member 63 is pressed at all times by means of the torsion spring 64. There is a stop pin 11 extending from the interior of the vertical wall of the housing 31 which limits movement in a counter-clockwise direction in Figure 2 of the downwardly depending portion of member 63. The downwardly depending portion of member 63 has a projection 80 thereon which at times is adapted to engage the leaf spring contact member 44 to close the circuit and stop the machine. It is noted that surface 13 recedes away from the lower end of member 63. In idle position the arm 52 is in the position shown in Figures 4, 6 or 8, and stop pin Tl prevents member 63 from engaging the surface 73 until the natural tension in a yarn in use raises the arm 52 to the position shown in Figure 2.

The shaft 32 has mounted thereon a collar 8| by means of a set screw 82 and this shaft projects from member H in which it is oscillatably mounted through the vertical side Wall of housing 31 and has an upwardly and. rearwardly turned arm 83 disposed inside the housing which also at times is adapted to engage the leaf spring member 44 to close the electrical circuit to stop the machine.

Method of operation With the yarn threaded through the mechanism as shown in Figures 1 and 3 and the yarn being knit, the parts will occupy the position shown in Figures 2 and. 3. The tension of the yarn will prevent portion 30 from passing through slot l3 and arm 52 will be held in the position shown in Figure 3. This will cause projection or arm 83 to be disposed in the position shown in Figures 3 and 7. In case of a sudden parting of the yarn, the portion 38 will move through the slot 43 to the position shown in Figure 6, and the parts will fall to the position shown in Figure 6 and this will cause upturned portion 83 (see Figure 2) to move over against the leaf spring member 44 and close the electrical circuit to stop the machine.

In case of a sudden parting of the yarn, the portion 30 will likewise fall to the position shown in Figure 6, but since the arm 52 will fall downwardly suddenly and not slowly and stop the machine as described, but in the event that the yarn associated with a particular stop motion is thrown out of operation, it very often happens that the vibration of the machine will cause the tension to gradually decreaseon the yarn which will allow the arm 52 to creep downwardly while the portion 33 has not yet passed through the slot l3. This will cause the projecting arm 60 to move upwardly into the cavity '5'! to the posi-' tion shown in Figure 4 and lock the shaft 32 against oscillation and therefore will prevent the portion 30 passing through the slot 13 far enough to cause the projecting portion 83 on the other end of the shaft to engage the leaf spring member 44 and thus the machine will not be stopped by a slackening of the tension in the yarn While that yarn associated with a particular stop motion mechanism is not in use.

' In the event of the tension becoming too great on the yarn, the arm 52 will be moved upwardly to the position shown in Figures 5 and 12 and the cam surface 13 will move the depending member 63 over against the leaf spring contact member 44 and stop the machine before the tension on the yarn is sufficient to break the same, and the yarn will slide off the end of member 53 after contact between members 63 and 44 has taken place.

Also, if desired, the shaft 25 can be cut off immediately adjacent the housing 31, but if desired it can be extended as shown in the drawings through the member ll and projected upwardly and inwardly as shown in Figure 3 and as the arm 52 is moved upwardly under increased tension of the yarn the portion 26 will pass in between the tension discs l1 and IS and tend to relieve the drag on the yarn before it reaches the point where the arm is high enough to cause the lower end of the member 63 to engage the leaf spring contact member 44 but in case this does not relieve the tension on the yarn sufficiently and the tension still increases, the parts will occupy the position shown in Figures 5 and 12 to close the circuit to stop the machine.

In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a stop motion for knitting machines and the like comprising a bracket grounded to the machine which forms one side of an electrical circuit and having a pair of uprising metallic members secured thereon, the first of said members near its upper end having a slot, an oscillatable shaft mounted in said members and having an upwardly projecting arm provided with a laterally extending portion adapted to pass through said slot and to be restrained against passing through said slot by a strand of yarn passing between the laterally projecting portion of the first member and the laterally projecting portion on the arm, the other end of the shaft having secured thereon adjacent the second uprising member a collar having a cavity in its lower surface, the shaft adjacent the collar having an uprising arm, a fixed contact member mounted adjacent the second uprising member and insulated from the bracket on which the uprising members are mounted, the electrical circuit having its other side connected to said fixed contact member, the fixed contact member extending upwardly and rearwardly adjacent and in the line of swing of the laterally uprising arm on said shaft, a second oscillatable shaft mounted in the second uprising member and having an arm extending therefrom beneath which a strand of yarn is adapted to be passed, a downwardly depending spring pressed member mounted on one side of the second uprising member, said second shaft having a collar thereon with a fiat surface on one side thereof and towards which the downwardly depending member is urged, the depending member having a projection extending toward the fixed contact member and swinging of the second shaft by an increase in tension of the strand being adapted to engage said projection with said fixed contact member to complete a circuit to actuate a conventional stop motion mechanism associated with the machine,

the second shaft having a rearwardly projecting arm integral therewith and adapted to rest in said cavity to lock the first shaft against oscillation upon stoppage of the machine due to a slackening of the yarn below a predetermined tension when not in use as the result of vibrations of the machine.

2. A stop motion mechanism for knitting machines and the like comprising a bracket grounded to the machine which forms one side of an electrical circuit, a pair of uprising metallic members electrically integral with the bracket and being spaced apart from each other, the first uprising member having a laterally projecting portion provided with a slot, a shaft oscillatably mounted in the two uprising members and having an upwardly projecting arm provided with a laterally extending portion adapted to pass through said slot and to be held against return through said slot by the passage of a strand of yarn between the two laterally projecting portions, the second uprising member having the other end of the shaft oscillatably mounted therein and the shaft having adjacent the second uprising portion an upwardly and rearwardly projecting contact member, a bolt penetrating the bracket and being insulated therefrom at a point adjacent the second uprising member and having secured to its upper end a rearwardly and upwardly projecting fixed contact member connected to the other side of the electrical circuit and adapted to be engaged by the contact member on said shaft, said shaft being positioned to oscillate by gravity as a result of the failure of a strand of yarn to pass between the laterally projecting portion of the shaft and the laterally projecting portion of the first member to close the circuit to stop the machine, the shaft having a collar fixed thereon provided with a cavity having a radially disposed shoulder, a second oscillatable shaft, the second upwardly projecting portion having a downwardly depending swinging member mounted therein and being spring pressed to move it toward the second shaft, the second shaft having a rearwardly projecting arm extending below the collar on the first shaft, the second shaft having a collar thereon provided with a fiat surface against which the downwardly depending member is urged, the downwardly depending member having a laterally projecting portion adapted at times to engage the fixed contact member associated therewith to close the circuit, the second shaft having extending therefrom an arm underneath which the strand of yarn is adapted to pass, excessive tension on the yarn serving to move the depending member against the fixed contact member to close the circuit, and parting of a strand serving to allow said arm beneath which the strand passes to fall downwardly to allow the rearwardly projecting portion thereon to engage the shoulder on said collar on the first shaft to prevent oscillatory movement of the first-named shaft upon a failure of tension in the yarn.

3. In a stop motion mechanism for knitting machines and the like an electrical circuit and first and second contacts in said electrical circuit normally held in open position, means controlled by the passage of a strand of yarn through the stop motion mechanism for holding the contacts in open position, one of said contacts being adapted to move against the other contact by gravity upon failure of the yarn, a third contact in said circuit and normally held away from the first contact, and means operable by an increase c eeses forming a part of said electrical, circuit, means 110;

controlled by the presence. of a strand of yarn passing through the stop motion device for preventing one of the movable contacts from engaging the fixed contact to stop the machine, means operable by an increase-inthe tension ofv the yarn m passing through the apparatus, beyond a predetermined tension for moving the second movable contact into contact with the fixed contact for stopping the machine and means for locking the first-named movable contact against movement upon a decrease in the tension of the yarn below a predetermined point.

5. In a stop motion device for knitting ma-v ch nes and the like comprising an electrical circuit, a fixed contact, in said circuit and first and second movable, contacts in said circuit adapted to; engage the fixed contact to stop the machine,

means controlled by the presence of a, strand ofyarnpassing through the stop motion device for preventing the; first movable contact, from engaging; the fixed, contact to stop the machine, means.

operableby an increase in the tension of the. strand passing through the device beyond a pre determined tension for moving the second movable contact into engagement with the fixed contact for closing the circuit and stopping the machine; and means for locking the first movable contact; against movement toward the fixed contact upon a gradual decrease in the tension of the. yarn.

CHARLES W. ARROWOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number: Name Date 2;19,0,5.21 Normandeau Feb. 13, 1940 2,420,513-

Arrowood May 13,v 1947 

